SACD vs. DVD-A
Feb 25, 2004 at 5:20 PM Post #17 of 174
Quote:

SACD has hybrid discs available that will play in any CD player, not just SACDPs. These discs contain a standard CD layer as well as a hi-rez stereo and occasionally, hi-rez multi-channel layers as well. These are sold as regular CDs in the regular section for the artist, most people are none the wiser they have a hybrid SACD as they are simply buying a "normal" CD for their collection.


Actually, that may be true for the major titles, such as those from Bob Dylan , Sam Cooke, or the Rolling Stones. Otherwise, even at a place such as Best Buy, you will still need to seek out the hybrid SACD version, for example Bon Jovi's latest release, in the SACD section.

Quote:

DVD-A is coming out with a flip-able version that will have a CD layer on one side and the hi-rez DVD layer on the other. Probably near the end of this year they will start to turn up.


Depending on where you are, they are available already. See this thread. And Sony is one of the participants, although they are not "piggybacking" a SACD onto a DVD-V disc.
 
Feb 25, 2004 at 6:32 PM Post #18 of 174
IMHO, both will, even if they succeed, will always remain niche markets. for the most part, the general public is not interested in the ultimate in sound quality.

for the record, i am a big fan of SACD fan (i have about 120 right now-90 hybrid, 30 single -layer)...i think the sonics are fantastic and a nice stepup from Redbook in general. but, i'm going to fool myself into thinking that it will become mainstream anytime soon. i bought a player because i thought there was enough software to interest me and the sonice upgrade was significant to my ears.
 
Feb 25, 2004 at 8:43 PM Post #19 of 174
Quote:

IMHO, both will, even if they succeed, will always remain niche markets. for the most part, the general public is not interested in the ultimate in sound quality.


Possibly, but OTOH, the CD is aging technology that they haven't yet found a reliable way to protect. SACD has the *potential* to provide superior copy-protection to the major labels, which is probably a larger incentive to switch and push this technology than we might think. They may latch onto it in a last-ditch attempt to preserve revenues. DVD-A also has superior *potential* copy-protection over the CD, but they do this by "digital water-marking" which is widely reported to be actually audible, thus irritating audiophiles and partially defeating the purpose of their superior resolution.

I think people can be convinced to switch over to SACD or even DVD-A if the transition can be made painlessly as it is with hybrid discs. Sony has realized the value of hybrids and has decreed recently that all future SACDs from them will be hybrid.

Mark
 
Feb 25, 2004 at 9:25 PM Post #20 of 174
Pet Sounds DVD-A is NOT 24/192. It is a 5.1 recording.

In order to do 24/192 the disc has to be stereo only. The highest sampling rate for a 5.1 channel recording is 24/96.

One company in conjunction with Muse announced some 24/192 recordings, but I have not seen them. I can't remember the company. I'll find out which one and whether they ever did come out with the recordings.

I have about 100 DVD-A's and about 40 SACD's. My brother works for WEA so I get their (DVD-A) releases for free. I also am associated with a studio that masters both SACD and DVD-A's.
 
Feb 25, 2004 at 9:33 PM Post #21 of 174
DVD-A and SACD are higher quality multi-channel capable formats. They way that I put it is that these formats are answers for questions that most consumers haven't asked.

CD's are already better than 99% of the systems are capable of reproducing. Most consumers care little about the sound quality. CD's succeeded because they were so much more convenient and durable than the LP's that they replaced, not because they sounded better.
 
Feb 25, 2004 at 9:33 PM Post #22 of 174
Quote:


I think people can be convinced to switch over to SACD or even DVD-A if the transition can be made painlessly as it is with hybrid discs. Sony has realized the value of hybrids and has decreed recently that all future SACDs from them will be hybrid.
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Agreeed. i bought some single-layers initially, but i only buy hybrids now. it's good insurance just in case the format and my player dies (and cannot be replaced).

i hope you're right. it would be fabulous to see SACDs hit the mainstream.

OTOH, if hybrids become the mainstream, they still haven't copyrighted against the low-fi ripping of the CD layer...
 
Feb 25, 2004 at 10:06 PM Post #23 of 174
Man, I still have not purchase any single-layer SACD.*

*I do have single-layer SACDs from Hong Kong that come with a CD of the same music.

Single-layer SACDs are fast becoming extinct, if they haven't already. And those that were released will soon be collector items.
 
Feb 25, 2004 at 11:39 PM Post #24 of 174
Quote:

Originally posted by Yikes
CD's are already better than 99% of the systems are capable of reproducing.


but that does not mean that we cannot appreciate sound that better than CD quality. Read this article

Quote:

Work done by Louis Fielder and Elizabeth Cohen suggest that a dynamic range of of 115 dB is required for natural reproduction in a good consumer environment. This considers a noise floor of about 4 dB SPL and a maximum level of 120 to 129 dB SPL for common musical performances in favored listening conditions, and accounts for limitations of equipment used.


The dynamic range quoted actually surpasses CD specs. food for thought I guess.
 
Feb 26, 2004 at 5:49 AM Post #25 of 174
uh, arent most consumer dvd players UNABLE to do dvd-a?

dont you need a 24/96 or 24/192 audio decoder, which only the higher end ones have?
 
Feb 26, 2004 at 6:49 AM Post #26 of 174
Quote:

Originally posted by adhoc
uh, arent most consumer dvd players UNABLE to do dvd-a?

dont you need a 24/96 or 24/192 audio decoder, which only the higher end ones have?


They're unable to play the DVD-Audio content, yes. From what I understand, every DVD-Audio disc also contains a DVD-Video layer with a Dolby Digital or DTS track set, and sometimes extras like music videos or interviews. So a DVD-A will play in any DVD player, but you're getting the Dolby Digital 5.1 version and not the high resolution multichannel or stereo tracks (which do require the better DACs and MLP decoding).
 
Feb 26, 2004 at 8:34 AM Post #27 of 174
DSD, or Direct Stream Digital, is an interesting concept. It's really just a special case implementation of a delta-sigma ADC/DAC, the same as those that have been serving as PCM ADC/DAC surrogates in the vast majority of recording and playback systems since the early 90's.

True PCM ADC/DAC's are actually bloody rare these days. Here's why: Take, for example, a 16-bit 44.1 Khz DAC such as you'd find in your typical CD player. You could build a circuit which would translate a 16-bit sample directly into an analogue signal. That is a true PCM converter. However, building a DAC that can create an analogue signal with 16-bits, or worse yet, 24-bits of precision is actually not easy or inexpensive. A delta-sigma DAC takes that PCM sample and converts it, via an interpolator, into a stream of one-bit samples. The actual DAC only has to be able to go higher or lower. If you use several million of these 1-bit samples per second you can achieve the same precision as as a 16-bit DAC operating at only a few thousand cycles per second. It's sort of like having an 80-year old granny on valium read a lottery number out versus playing higher/lower with a professional auctioneer. Both can get convey roughly the same thing in the same ammount of time, but how they do it is quite different. It turns out that building such inprecise but amazingly fast DAC's is quite cheap. This is why the odds are that almost every PCM DAC or ADC in any audio device you own is probably a delta-sigma ADC or DAC.

A delta-sigma DAC or ADC, although typically just one chip or component, can be viewed as a string of components. The stream of 1-bit samples in between the interpolator and 1-bit DAC in a delta-sigma DAC is basically what DSD is. The only difference is that the sample rate in your typical delta-sigma DAC is much higher than the sample rate of DSD as implemented for SACD's. Still, DSD has a high enough sample rate to get the job done. By eschewing the conversion to PCM, SACD's appeal to old-fasioned analogue audiophiles who are used to trying to eliminate every signal degrading device in a signal path. This is all happening in the digital domain however, so that little appeal is totally without merit. Still, a lot of SACD fans will trumpet the simple signal patch of DSD devices.

The truth is, while DSD is an interesting technology on paper that has some conceptual elegance, it's not really a step forward. PCM is actually a more compact way of storing data. DSD is theoretically easier to embed digital watermarks in and as a result may make some copy protection schemes easier to implement. That's not really a major plus for consumers however.

Currently, DVD-A's can hold more audio data of a given quality than SACD's can. DVD-A's are also considerably more flexible to author. As others have pointed out, this is not an advantage for consumers, since it only means more corners are possible to cut. This is pretty much academic however.

The biggest barrier that both high-resolution audio formats face is that almost nobody has a system capable of benefiting from high-resolution audio. That's not going to change anytime soon either. For the average consumer, there is no perceived value to a DVD-A or SACD over a standard redbook audio CD. As long as high-resolution formats remain more expensive to author, produce, and purchase they simply aren't going to catch on. Fortunately, costs will go down over time and we'll probably see high-resolution audio gradually phase out redbook CD's. This isn't going to happen nearly as fast as CD's phased out tapes or LP's though. (As if that was fast... You can still buy both almost three decades after CD's came out!) Of course, it should also be noted that we're not exactly awash with well-authored CD's right now either. People should know what they're doing by now, but it's amazing how they find new ways of getting it wrong. Just look at all the pop that is being mastered so hot these days that it's like listening to square waves. A lot of albums made these days by major record companies who *should* know better clip pretty much continually! If the big boys can't get redbook CD's right, what hope is there for high resolution audio?

The end verdict is that any audio format is only as good as the recording and authoring that goes into it.
 
Feb 26, 2004 at 10:14 AM Post #28 of 174
Quote:

Originally posted by Cor

A delta-sigma DAC or ADC, although typically just one chip or component, can be viewed as a string of components. The stream of 1-bit samples in between the interpolator and 1-bit DAC in a delta-sigma DAC is basically what DSD is. The only difference is that the sample rate in your typical delta-sigma DAC is much higher than the sample rate of DSD as implemented for SACD's. Still, DSD has a high enough sample rate to get the job done. ...


Cor,

This is simply going over old ground, and a lot of your post is materially incorrect, however I will take time to address just a few points. Yes PCM is a base storage medium. However, your arguments amount to saying that a train and a car are materially equivalent because they both run on wheels. When folks state what you say, I always ask the rhetorical question, Does Sigma Delta modulation (from now on referred to as SDM) only apply to 1-bit words?

SACD's base sampling rate 2.8 MHz is much like having a CD with 44.1 KHz. Once you are inside the DAC, you can oversample to higher sampling frequencies to your heart's content as long as the silicon technology holds. Secondly the fundamental difference between PCM and DSD is that PCM stores an absolute value and DSD stores a relative value. Secondly, PCM trades off word length against sampling frequency, whereas SDM trades off sampling frequency against wordlength and there are advantages and disadvantages to both approaches.

An Interpolator is used to oversample to higher frequencies and longer word lengths. The word you are looking for is a differentiator, and you can differentiate any sigma-delta word to a PCM word. As I mentioned in another thread a while ago, a 1-bit sample is a special (or initial) condition since the LSB and MSB are one and the same and a valid word must be >0. That special condition is what has fundamental significance. However, you can always oversample to a higher frequency and a longer word length and once your sample is greater than 1-bit, the special condition ceases to hold.

Lastly your remarks that Quote:

Currently, DVD-A's can hold more audio data of a given quality than SACD's can.


is factually incorrect, if that were the case why are MCH DVDAs stuck at 96/24 and stereo DVDAs can achieve 192/24

Quote:

DVD-A's are also considerably more flexible to author.


This has not been borne out in the field, in fact one of the comments made by one of the mastering houses is that because SACD is an audio only format it is easier to master than the hybrid AV format that is DVDA. Looking at the considerable inconsistency in operating existing DVDAs I do not think he is far away from the truth. I am sure here what you trying to say is that PCM is easier to DSP, however that will be the case with most old technologies vis a vis their newer competitors.
 
Feb 26, 2004 at 3:27 PM Post #29 of 174
Quote:

The biggest barrier that both high-resolution audio formats face is that almost nobody has a system capable of benefiting from high-resolution audio. That's not going to change anytime soon either. For the average consumer, there is no perceived value to a DVD-A or SACD over a standard redbook audio CD.


Then how come it's very easy to tell the difference between the SACD layer and the Redbook layer on even budget SACDPs? The difference is there, and it's easily perceptible, especially on lower-end gear.

One of the major revelations for me after finally getting a source that did justice to the Redbook CD (555ES Hot Rod), after owning three other $1000-$1600 hi-rez sources (and numerous other better quality CDPs), was that the difference between SACD and Redbook gets smaller and smaller on better and better systems. My current feeling (which is subject to change) is that the real benneficiaries of the Hi-Rez formats will be people with budget systems, it's now possible to provide high-quality audio on cheaper and cheaper systems with hi-rez. Because the media is so good, the playback doesn't have to be quite as good to get good sound.

Mark
 
Feb 27, 2004 at 1:33 AM Post #30 of 174
Quote:

An Interpolator is used to oversample to higher frequencies and longer word lengths. The word you are looking for is a differentiator, and you can differentiate any sigma-delta word to a PCM word.


If you look at a DS PCM chain from analogue to analogue it looks like this:

Analogue -> 1-bit ADC -> DS Stream -> Decimator -> PCM samples -> Interpolator -> DS Stream -> 1-bit DAC -> Analogue

I was talking about DAC's above, so an Interpolator was the correct beast. You shouldn't find a Decimator anywhere in a DSPCMDAC.

Quote:

is factually incorrect, if that were the case why are MCH DVDAs stuck at 96/24 and stereo DVDAs can achieve 192/24


In theory, 24-bit 96 KHz. PCM does actually contain more data than 1-bit 2.8224 MHz. DSD. PCM also losslessly compresses more. (Both DVD-A and SACD employ lossless compression algorithms) Hence, given the same raw capacities, you *should* be able to fit more music of a given quality onto a DVD-A. Of course, we're splitting hairs here. Most discs aren't close enough to being full for this to matter.

Quote:

This has not been borne out in the field, in fact one of the comments made by one of the mastering houses is that because SACD is an audio only format it is easier to master than the hybrid AV format that is DVDA.


DVD-A's can be authored in 96/24, 192/24, and several other bit-depth/sample-rates. You could author a DVD-A in 16-bit 44.1 Khz if you really wanted to. With SACD's you have one option: 2.8224 MHz DSD. My point is that while DVD-A at it's best competes well with SACD, it is possible to author DVD-A's that are grossly inferior just by choosing a low bit-depth/sample-rate. Yes, it's a damned silly thing to do, but never underestimate peoples' capacity for stupidity.

Quote:

This is simply going over old ground, and a lot of your post is materially incorrect, however I will take time to address just a few points.


Thanks for being so polite about it.
biggrin.gif


Quote:

Then how come it's very easy to tell the difference between the SACD layer and the Redbook layer on even budget SACDPs? The difference is there, and it's easily perceptible, especially on lower-end gear.

One of the major revelations for me after finally getting a source that did justice to the Redbook CD (555ES Hot Rod), after owning three other $1000-$1600 hi-rez sources (and numerous other better quality CDPs), was that the difference between SACD and Redbook gets smaller and smaller on better and better systems. My current feeling (which is subject to change) is that the real benneficiaries of the Hi-Rez formats will be people with budget systems, it's now possible to provide high-quality audio on cheaper and cheaper systems with hi-rez. Because the media is so good, the playback doesn't have to be quite as good to get good sound.


So you are arguing that a good system can make inferior sources sound almost as good as superior sources, but on a crappy system the superior source will sound far better? It's has always been exactly the opposite in my experience, but perhaps you're hearing something that I'm not.
 

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